The Harbor Mid Cap Value Fund is subadvised by LSV Asset Management. The Fund invests primarily in equity securities, common stocks, of mid cap companies that the portfolio manager believes are undervalued in the marketplace at the time of purchase. The portfolio manager's investment strategy uses a quantitative model to evaluate and recommend companies based on the following indicators:

As of Quarter Ended 09/30/2016

YTD

1 Year

5 Year

10 Year

Since Inception

7.61%

9.96%

17.94%

7.28%

9.37%

Growth of a Hypothetical $10,000 Investment

Source: Morningstar, Inc.

Potential Risk & Return - Domestic Equity Funds

Performance data shown represents past performance, which is no guarantee of future results. Current performance may be higher or lower than the past performance data shown. Investment returns and the value of an investment will fluctuate, and an investor's shares, when sold, may be worth more or less than their original cost. You can obtain performance data current to the most recent month-end (available within seven business days after the most recent month-end) by calling 800-422-1050 or visiting www.harborfunds.com.

The Harbor Funds performance shown assumes the reinvestment of dividend and capital gain distributions and is net of management fees and expenses. Returns for periods less than one year are not annualized.

From time to time, certain fees and/or expenses have been voluntarily or contractually waived or reimbursed, which has resulted in higher returns. Without these waivers or reimbursements, the returns would have been lower. Voluntary waivers or reimbursements may be applied or discontinued at any time without notice. Only the Board of Trustees may modify or terminate contractual fee waivers or expense reimbursements.

The Russell Midcap® Value Index is an unmanaged index generally representative of the U.S. market for medium capitalization value stocks. This unmanaged index does not reflect fees and expenses and is not available for direct investment. The Russell Midcap® Value Index and Russell® are trademarks of Russell Investments.

The Harbor Mid Cap Value Fund received a 4-star Overall Morningstar Rating™ as of 09/30/2016 out of 399 Mid-Cap Value funds. Mid Cap Value Fund was rated 5-star among 348, 3-star among 239, and 0-star among 0 domestic Mid-Cap Value funds for the three-, five- and ten-year periods ended 09/30/2016, respectively. The Morningstar Rating is for the Administrative share class only; other classes may have different performance characteristics.

For each fund with at least a three-year history, Morningstar calculates a Morningstar Rating™ based on a Morningstar risk-adjusted return measure that accounts for variations in a fund's monthly performance (including the effects of sales charges, loads, and redemption fees), placing more emphasis on downward variations and rewarding consistent performance. The top 10% of funds in each category receive 5 stars, the next 22.5% receive 4 stars, the next 35% receive 3 stars, the next 22.5% receive 2 stars and the bottom 10% receive 1 star. The Overall Morningstar Rating for a fund is derived from a weighted average of the performance figures associated with its three-, five- and ten-year (if applicable) Morningstar Rating metrics.

Investors should carefully consider the investment objectives, risks, charges and expenses of a Harbor fund before investing. To obtain a summary prospectus or prospectus for this and other information, visit harborfunds.com or call 800-422-1050. Read it carefully before investing.

All trademarks or product names mentioned herein are the property of their respective owners.

The Adviser has contractually agreed to reduce the management fee to 0.70% on assets over $500 million through February 28, 2017. Only the Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

The Adviser has contractually agreed to reduce the management fee to 0.70% on assets over $500 million through February 28, 2017. Only the Board of Trustees may modify or terminate this agreement.

Restated to reflect current fees.

Ex-Date. The date on which a Fund's net asset value (NAV) will fall by an amount equal to the dividend and/or capital gain distribution plus or minus any change in the value of the Fund's holdings.

About Expense Ratios: All mutual funds have expense ratios which represent what shareholders pay for operating expenses and management fees. Expense ratios are expressed as an annualized percentage of a fund's average net assets paid out in expenses. Net expense ratios reflect adjustments due to voluntary or contractual fee waivers or expense reimbursements. Expense ratio information is as of the Fund's current prospectus, as revised and supplemented from time to time.